Memory cartridge-connectable electronic device such as electronic still video camera

ABSTRACT

In a combination of an electronic device and a memory cartridge loaded in the device, a direct check is performed to determine if the device and memory cartridge are properly coupled. To this end, the electronic device writes a predetermined code in a predetermined area of a memory within the memory cartridge and subsequently reads the code out of the memory. Whether or not the coupling between the device and cartridge is normal is judged by comparing the written code and the read code. Alternatively the memory cartridge is provided with checking code generating means. A checking code generated by the generating means when the memory cartridge is loaded in the electronic device is checked on the electronic device side to judge whether the coupling is normal. An example of the electronic device is an electronic still video camera in which photography is enabled only when it is judged that the coupling between the camera and the memory cartridge is normal.

This application is a divisional of copending application Ser. No.07/191,064, filed on May 6, 1988.

BACKGROUND OF THE INVENTION

This invention relates to an electronic device, such as an electronicstill video camera, which, on the basis of a physical signal (such as anelectric signal, magnetic signal or optical signal ), is capable ofbeing coupled to a memory cartridge when the cartridge is loaded in thedevice at a predetermined location thereof. The electronic still videocamera mentioned here refers to a camera which stores a video signalrepresenting a still picture in a memory device in the form of digitaldata.

Attempts have been made to develop IC cards, CPU cards and memory cards,which incorporate an internal semiconductor element such as an IC or asemiconductor device, for use in a wide variety of fields as asubstitute for conventional magnetic cards, a substitute for externalmemories such as floppy discs, and as novel electronic media or controlmeans. Some of these cards have been put into practical use. When such acard is loaded in a prescribed location of an automatic machine, controldevice or other electronic device, the device and the card are renderedconnectable by a physical signal, such as an electric signal, magneticsignal or optical signal. More specifically, connection terminals on thecard can be connected to a connector on the side of the electronicdevice, or coupling can be achieved magnetically or optically. Underthese conditions, the electronic device and the card can communicatewith each other and the electronic device can execute card processing,such as writing data in the memory of the card.

In general, an IC card, a CPU card and a memory card are physicallyhandled and, as a result, the connection terminals tend to pick upgrease, dust and other foreign matter, which can lead to a poorconnection. When the connection terminals do not make good contact withthe connector of the electronic device, the aforementioned cardprocessing cannot take place normally. In other words, a faultyconnection can cause errors to appear in the communications between theelectronic device and the card and can make it impossible to write datainto the memory of card correctly.

One conceivable application of a memory card having a comparativelylarge-capacity memory is as a medium for storing image data picked up bya digital electronic still video camera. Since a camera of this kind canbe used outdoors as well as indoors, the connection terminals of thememory card easily pick up moisture and therefore tend to oxidize andcorrode. This is a cause of faulty connections, which can make correctrecording of video data impossible. A memory card provided with a verylarge memory capacity will predictably have a large number of connectionterminals. Since reliable recording cannot be expected even if only oneof these terminals develops a faulty connection, there is greater riskof recording failure.

The adherence of dust or other contaminants can lead to a faultyconnection not only in instances where coupling depends upon theelectrical contact between the connection terminals of the card and theconnector of the electronic device but also in cases where coupling isachieved magnetically or optically.

Correct card processing also cannot be expected if the loading (as byinsertion) of the card into the electronic device is not performed inthe proper manner.

The special circumstances concerning an electronic still video camerawill now be described in detail.

An electronic still video camera described in the specification ofJapanese Patent Application Laid-Open (KOKAI) No. 59-183592 includes acamera body having an imaging optical system and a solid-state imagepick-up device and is connected to a loadable/unloadable memory whichstores, in the form of a digital signal, a video signal representing astill picture imaged by the image pick-up device. The memory storing thevideo signal is removed from the camera and loaded in a playbackapparatus. The playback apparatus reads the video signal out of thememory and reproduces the video signal as a visible picture on thescreen of a video monitor.

When photography is performed using an electronic still video camera ofthis type, it is necessary to load the memory in the camera accuratelyin order to connect the memory to the camera circuit-wise, after whichphotography is performed to produce a video signal which is then storedin the memory. However, since the electrical circuit-wise connection ofthe memory cannot be detected in this conventional electronic stillvideo camera, it is impossible for the operator to know at the time thatthe memory is loaded whether the memory has actually been connected tothe camera in terms of the electrical circuitry. If the connection hasnot been made, therefore, a video signal will not be stored in thememory even if the photographer takes a picture of a subject. This meansthat the photographer will have wasted his time since the picture whichshould have been taken will not be recorded.

Furthermore, in spite of the fact that the video signal is not beingstored in the memory, the electronic still video camera willnevertheless image the subject being shot, convert the resulting videosignal into a digital signal, create color separation information,optical distortion information and various types of data necessary forplayback on a playback apparatus, and deliver these signals and data toconnection means. Power is thus consumed wastefully.

SUMMARY OF THE INVENTION

An object of the present invention is to make it possible to check thecoupling between an electronic device and e.g. an IC card, a CPU cardhaving a memory, a memory card or a semiconductor memory module(referred to generally as "memory cartridges") by comparatively simpleprocessing.

Another object of the present invention is to provide a signalelectronic still video camera capable of performing photographicoperations only after a memory cartridge has been positively connectedto the camera and video signals are capable of being recorded.

The present invention provides an electronic device which, when a memorycartridge having a memory is loaded in the electronic device, is capableof coupling with the memory cartridge based on a physical signal, theelectronic device comprising first sensing means for sensing that thememory cartridge has been loaded at a prescribed location in theelectronic device, writing means for designating a predetermined addressin the memory of the memory cartridge and writing a predetermined codeat the predetermined address when loading of the memory cartridge hasbeen sensed by the first sensing means, reading means for reading thecode written by the writing means out of the memory, and second sensingmeans for sensing coincidence between the code written by the writingmeans and the code read by the reading means.

When coincidence is not sensed, this means that coupling is faulty. In apreferred embodiment, therefore, means are provided for outputting awarning signal when coincidence is not sensed.

In a preferred embodiment, the aforementioned writing, reading andcoincidence sensing processing is executed a number of times changingthe address or the code or both.

The memory cartridge refers to an arrangement in which the memory ishoused in a case such as a card-shaped case or box-shaped case, as wellas to a semiconductor memory module. It goes without saying that theconcept of a memory cartridge covers not only one having a CPU and amemory and one further including a liquid crystal display device and akeyboard, but also one having only a memory and no CPU or one having arequired power supply and some other circuitry in addition to a memory.Furthermore, as mentioned above, the type of coupling between the memorycartridge and the electronic device includes not only electrical contactbetween the connection terminals of the memory cartridge and theconnector of the electronic device but also optical coupling, whichcomprises one or a plurality of light-projecting elements provided onone of the memory cartridge and electronic device and one or a pluralityof light-receiving elements provided on the other of the memorycartridge and electronic device, and magnetic coupling, comprising coilmeans or the like.

In accordance with the invention, a predetermined code from theelectronic device is transmitted to the memory cartridge through theaforementioned physical coupling and the code is written in the memory.The code that has been written in the memory is read by the electronicdevice, and it i determined whether the read code coincides with thewritten code. If coincidence is detected, then a decision is renderedthat the physical coupling is normal. If coincidence is not detected,however, the decision rendered is that the physical coupling isabnormal.

Thus, processing for determining whether or not the memory cartridge andelectronic device are coupled normally can be performed after acomparatively short period of time and in a comparatively simple manner.

A device for checking the state of coupling between a memory cartridgeand an electronic device in accordance with the invention comprises amemory cartridge having a memory and first coupling means, and anelectronic device having a second coupling means, wherein when thememory cartridge is loaded in the electronic device, the electronicdevice is capable of being coupled with the memory cartridge through thefirst and second coupling means on the basis of a physical signal.

The memory cartridge is provided with means for generating a checkingcode, and changeover means for changing over a connection between thefirst coupling means and the memory or the checking code generatingmeans.

One of the memory cartridge and the electronic device is provided withmeans for sensing that the memory cartridge has been loaded in theelectronic device at a predetermined location thereof, and control meansfor controlling the changeover means in such a manner that the checkingcode generating means is connected to the first coupling means whenloading of the memory cartridge in the electronic device has beensensed.

The electronic device is provided with means for examining the checkingcode transmitted by the checking code generating means via the first andsecond coupling means, and for determining whether coupling performed bythe first and second coupling means normal or abnormal.

In accordance with the invention, when the memory cartridge is loaded inthe electronic device, the predetermined code generated in the memorycartridge is transferred to the electronic device through the first andsecond coupling means, and the electronic device examines the code todetermine if it is the predetermined one. If this is determined to bethe fact, the electronic device decides that the coupling between it andthe memory cartridge is normal. If non-coincidence is detected, theelectronic device decides that the coupling is abnormal.

Thus, processing for determining whether or not the memory cartridge andelectronic device are coupled normally can be performed after acomparatively short period of time and in a comparatively simple manner.

Further, in accordance with the invention, there is provided a digitalelectronic still video camera to which a memory cartridge is connectedin a loadable/unloadable manner, the memory cartridge storing, in theform of digital data, a video signal representing a still picture, thecamera comprising: connecting means to which the memory cartridge isconnected circuit-wise in a loadable/unloadable manner; image pick-upmeans having a solid-state image pick-up device and adapted to image asubject by the solid-state image pick-up device and output a videosignal representing the subject; signal converting means for convertingthe video signal outputted by the image pick-up means into acorresponding digital signal and outputting the digital signal to theconnecting means; and control means for controlling the image pick-upmeans and signal converting means to cause the image pick-up means toperform imaging and cause the signal converting means to convert theoutputted video signal into a digital signal, and for supplying theconnecting means with a control signal for controlling writing into thememory cartridge; the control means including information generatingmeans for generating information for verifying that the memory cartridgehas been connected to the camera electrical circuit-wise by theconnecting means, and information verifying means for verifying theinformation generated; wherein when the memory cartridge is loaded inthe camera, the control means sends the information generated by theinformation generating means to the memory cartridge, and enables eachfunctional part of the camera to perform a photographic operation afterthe information verifying means verifies that the information has beenstored in the memory cartridge.

Thus, in accordance with the invention, power is not supplied whenloading of the memory cartridge is not sensed. This makes it possible toprevent photographic errors due to a faulty connection between thememory cartridge and the camera. Furthermore, a code for checking theconnection to the memory cartridge is written in the memory, andphotography is made possible after sensing that this information hasbeen written in the memory. This prevents the occurrence of a situationin which a video signal cannot be recorded in the memory. Wastefulconsumption of power can therefore be avoided.

Since photography is made possible only after information necessary forplayback is written in the memory beforehand, it is possible to avoid asituation in which the information necessary for playback is not storedin the memory.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an embodiment of the present invention and shows thestate of a connection between an electronic device and a memorycartridge, as well as the electrical construction of the device andcartridge;

FIG. 2 is a flowchart illustrating a connection checking processingprocedure;

FIG. 3 is a view showing another example of sensing loading of a memorycartridge;

FIG. 4 illustrates another embodiment of the present invention and showsthe state of a connection between an electronic device and a memorycartridge, as well as the electrical construction of the device andcartridge;

FIG. 5 is a functional block diagram illustrating yet another embodimentof the present invention and showing a digital electronic still videocamera;

FIG. 6 is a circuit diagram illustrating a specific example of aconnection sensing circuit included in the arrangement of FIG. 5;

FIG. 7 is a circuit diagram illustrating another example of theconnection sensing circuit; and

FIG. 8 is a functional block diagram illustrating an exemplaryarrangement of a playback apparatus which plays back a video signalstored in a memory by the camera embodied in FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates the state of a connection between an electroniccontrol device 10 and a memory cartridge 20.

The electronic device 10 is a device, such as a digital electronic stillvideo camera, which requires the memory cartridge 20 as a medium forstoring desired data. The electronic device 10 is provided with a recessor guide 15 in which the memory cartridge 20 is loaded, as by beinginserted. The portion of the memory cartridge 20 that is inserted intothe recess 15 is formed to have a number of connection terminals 24.Provided in the recess 15 of the electronic device 10 is a connector 14having terminals equivalent in number to the terminals 24 forelectrically contacting these terminals when the memory cartridge 20 isloaded. Also disposed in the recess 15 is a limit switch 16 for sensingthat the memory cartridge 20 has been loaded in the recess 15 in properfashion. The limit switch 16 produces a detection signal applied to aCPU 11. It is possible to sense the loading of the memory cartridge 20by any of a variety ofsensors, such as a photoelectric switch forsensing loading optically, or a switch for sensing loading magnetically.It is possible to sense loading of the memory cartridge 20 by electricalsensing means such as shown in FIG. 3. One terminal 14a of the connector14 of electronic device 10 is connected to the ground of the electronicdevice, and one other terminal 14b of the connector 14 is connected tothe CPU 11 through an amplifier if necessary. Terminals 24a, 24b of thememory cartridge 20 that are to be connected to respective ones of theterminals 14a, 14b are connected to each other and to the ground of thememory cartridge. When the memory cartridge 20 is loaded in theelectronic device 10, ground-level signals are applied to the CPU 11through the terminals 14a, 24a, 24b, 14b. The CPU 11 is thus capable ofsensing that the memory cartridge 20 has been loaded.

The electronic device 10 is provided with the abovementioned CPU 11,which controls various operations in the electronic device and executesprocessing, described below, to check the connection of the memorycartridge. The electronic device 10 is also provided with an alarmdevice 19, such as a buzzer or light-emitting diode, which informs anoperator of the fact that the checked connection has been determined tobe faulty when such a determination is made. The alarm device 19 isconnected to the CPU 11.

The memory cartridge 20 has several internal memory chips 21. Ifvolatile, these memories incorporate a power supply such as a battery.

Some of the terminals of connector 14 and the corresponding connectionterminals 24 of memory cartridge 20 are for transmitting an addresssignal used to address the memory in the memory cartridge 20. Some ofthe other of these terminals are for transferring data. Furthermore, oneor a plurality of the terminals is for transmitting a chip-select signalCS, and one or a plurality is a terminal for a read/write command R/Wfrom the CPU 11. These terminals in connector 14 are connected to theCPU 11 by an address bus, data bus and control lines for the signals CS,R/W. The terminals 24 of memory cartridge 20 are also connected torespective ones of the address bus, data bus and control lines connectedto the memory chips 21. Accordingly, when the memory cartridge 20 isloaded in the electronic device 10, the address bus, data bus andcontrol lines inside the electronic device 10 are connected to thecorresponding buses and lines in the memory cartridge 20 via theconnector 14 and terminals 24, and it becomes possible for the CPU 11 ofelectronic device 10 to directly access the memory of the memorycartridge 20.

Depending upon the particular case, a connection terminal is alsoprovided in order to connect a power supply line for the purpose ofsupplying the memory cartridge 20 with electric power from theelectronic device 10.

FIG. 2 shows the general features of a connection checking processingexecuted by the CPU 11.

When the limit switch 16 issues a detection signal indicating that thememory cartridge 20 has been loaded at step 101, the CPU 11 outputs anaddress signal, which designates a predetermined address of the memoryin memory cartridge 20, as well as the chip select signal, sends apredetermined code out on the data bus, and outputs a write command(step 102). As a result, the abovementioned code is written in thedesignated storage location of the memory in memory cartridge 20. Next,the CPU 11 outputs an address signal designating the same address asmentioned above, a chip-select signal and a read command, and reads thepreviously written code out of the same storage location through thedata bus (step 103). The CPU 11 compares the code that was transmittedfor the purpose of being written and the code read in response to theread command, and determines whether the two codes coincide (step 104).If the two codes coincide, the same processing is repeated upon alteringat least the address or the code data (step 105). When writing, readingand comparing processing regarding combinations of given addresses andcodes ends, connection checking processing is terminated and the programproceeds to predetermined processing relating to the memory cartridge20, e.g. to processing for writing video data in a predetermined memoryarea. If the two codes are found not to coincide at the step 104, acommand is applied to the alarm device 19, which responds by issuing analarm indicative of non-coincidence (step 106).

By way of example, in the first cycle of processing, a signal composedof all 0's (i.e. a signal in which all bits are zero) is applied as anaddress signal (inclusive of the chip-select signal), and data in which1 and 0 repeat alternatingly starting from 1, as in the manner 1010 . .., is applied as a code. The checking processing of steps 102 through104 is executed based on this address signal and code. In the secondcycle of processing, an address signal composed of all 1's and data 0101. . ., in which the code is reversed, are applied and the processing ofsteps 102 through 104 is executed in the same manner. By adopting suchan arrangement, 1 and 0 signals are transmitted through all terminals ofconnector 14 and all of the corresponding connection terminals 24 in atleast two processing cycles. Accordingly, if a YES decision(coincidence) is rendered at the step 104 in each of these processingcycles, then this will mean that all of the terminals are in asatisfactorily connected state.

It goes without saying that the combinations of address signals andcodes given by the CPU 11 can be selected at will.

If necessary, an arrangement can be adopted in which, when a NO answeris received at the step 104, thereby indicating that the connection isfaulty, the program proceeds to warning processing only if a YES answerstill is not received even after the processing for designating the sameaddress, transmitting the same code and reading out the code is repeateda predetermined number of times. In a configuration having an automaticloading mechanism which loads the memory cartridge automatically, it canbe arranged so that the memory cartridge is ejected once and thenreloaded when a NO answer is received at the step 104.

FIG. 4 illustrates another embodiment of the invention. Portions in FIG.4 which are identical with those of FIG. 1 or which implement the samefunctions are designated by like reference characters and are notdescribed again.

In this embodiment, the electronic device 10 is provided with a systemcontroller 11 including a CPU for controlling various operations of theelectronic device 10 and executing processing to check the connection ofthe memory cartridge 20. An alarm device (not shown) is connected to thesystem controller 11 for informing an operator of the fact that thechecked connection has been determined to be faulty when such adetermination is made. If the electronic device 10 is a digitalelectronic still video camera, video data to be written in the memory 21of the memory cartridge 20 is applied from an image pick-up device (notshown) to an A/D converting and signal processing circuit 12 in the formof an analog signal. The circuit 12 subjects the video to an A/Dconversion and predetermined signal processing, thereby producingpicture data applied to a three-state buffer 13 by the data bus. Athree-state buffer is one which can establish a high output impedence inresponse to a control signal inputted thereto, with the signal obtainedfrom the output side of the buffer at such time inhibiting an input tothe buffer. A three-state buffer ordinarily has a low output impedence,with a signal applied to the input side thereof being introduced to theoutput signal intact. An address bus and a control bus from the systemcontroller 11 are connected to the three-state buffer 13. The outputside of the buffer is connected to the connector 14 and also to thesystem controller 11.

The memory cartridge 20 is provided with a memory 21 including one or aplurality of memory chips, a checking code generating circuit 22 forgenerating a predetermined checking code, a multiplexer 23 for changingover connection between the terminals 24 and the memory 21 or generatingcircuit 22, and a power supply (not shown), such as a battery, forsupplying the generating circuit 22 with electric power. Normally, themultiplexer 23 connects the terminals 24 to the memory 21 (side a). Uponreceiving a changeover control signal from a terminal 24A, themultiplexer 23 connects the output side of the checking code generatingcircuit 22 to the terminals 24 (side b) for a fixed period of time.

As mentioned earlier, some of the terminals of connector 14 and thecorresponding connection terminals 24 of memory cartridge 20 are fortransmitting an address signal used to address the memory of the memorycartridge 20. Some of the other of these terminals ar for transferringdata. Furthermore, there are terminals for transmitting a chip-selectsignal CS, a read/write command R/W and control signals such as theabovementioned changeover control signal (terminal 24A). Accordingly,when the memory cartridge 20 is loaded in the electronic device 10, theaddress bus, data bus and control lines inside the electronic device 10are connected to the corresponding buses and lines in the memorycartridge 20 via the connector 14 and terminals 24, and it becomespossible for the CPU of the system controller 11 in electronic device 10to directly access the memory of the memory cartridge 20. Since achecking code is used in order to check the state of the connectionsbetween all of the terminals 24 and all of the terminals of connector14, the checking code generated by the generating circuit 22 is appliedto all of the terminals 24 (except for terminal 24A) via the multiplexer23.

The general features of connection checking processing executed by theCPU of electronic device 10 will now be described.

When the limit switch 16 issues a detection signal indicating that thememory cartridge 20 has been loaded, the CPU of controller 11 outputsthe changeover control signal. This signal is applied to the multiplexer23 and checking code generating circuit 22 via the terminal 24A and thecorresponding terminal of connector 14. Accordingly, the output side ofthe checking code generating circuit 22 is connected to the terminals 24and the circuit 22 generates a predetermined checking code. At the sametime, the system controller 11 applies a control signal to thethree-state buffer 13, whereby the output side thereof attains a highimpedence. The checking code generated by the generating circuit 22 isapplied to the system controller 11 through the multiplexer 23,terminals 24 and connector 14. Since the buffer 13 presents a highoutput impedence (a high input impedence with regard to the checkingcode), the checking code does not enter the buffer 13.

The CPU of the system controller 11 investigates the inputted checkingcode to determine whether it is a predetermined code. This can beachieved by previously storing a checking code in the controller 11, andhaving the controller 11 compare this code with the inputted checkingcode to determine if they coincide. Alternatively, if the checking codegenerated by the circuit 22 exhibits a certain regularity (e.g. 1's and0's repeating in alternating fashion starting with 1, such as 1010 . ..), checking can be performed by investigating the code for thisregularity. Preferably, it is arranged so that the generating circuit 22successively generates two or more types of checking codes to transmit 1and 0 signals through all of the terminals 24 and all of the terminalsin the connector 14. If no abnormality is found as a result ofinvestigating all of the checking codes, then the CPU stops outputtingthe changeover control signal to switch the multiplexer 23 over to theside of memory 21, and the circuit 22 stops generating the checkingcode. The program then proceeds to predetermined processing regardingthe memory cartridge 20, such as processing for writing video data in apredetermined memory area. If even one bit is found to be erroneous as aresult of investigating the checking code, a command is applied to thealarm device, which responds by issuing an alarm to this effect.Obviously, depending upon the particular case, an arrangement can beadopted in which an alarm is issued only if a decision indicative of anormal connection is not rendered after the checking processing isrepeated a plurality of times.

It is permissible to adopt an arrangement in which, if the memorycartridge possesses a CPU, the checking code is generated by this CPU.An arrangement is also possible in which the memory cartridge isprovided with a cartridge loading detection switch, and a CPU within thecartridge responds to loading detection by changing over the multiplexer23 and starting generation of the checking code.

Furthermore, in the above-described arrangement shown in FIG. 3, apredetermined voltage can be applied to the terminal 14a, with thechangeover of multiplexer 23 and the generation of the checking codebeing initiated by a voltage which will appear at the terminal 24a whenthe memory cartridge is loaded. In this case, the voltage impressed uponthe terminal 24a would be sent to ground potential at the end of thechecking operation. Alternatively, the cartridge could be provided witha timer for controlling the checking time period. When time runs out,the multiplexer would be returned to the memory side and the generationof the checking code would be terminated.

An embodiment of a digital electronic still video camera in accordancewith the present invention will now be described. Portions identical orsimilar to those described above are designated by like referencecharacters.

FIG. 5 illustrates an embodiment of a digital electronic still videocamera in accordance with the present invention. The embodiment includesan electronic still video camera 10 having an image pick-up section 30,and a memory cartridge 20 connected to the camera 10 via a connector 17in loadable/unloadable fashion. Conceptually, the connector 17 includesthe above-described connector 14 and terminals 24. The connector 17includes a connector portion 18, described below.

The memory cartridge 20 includes, for example, an SRAM semiconductormemory 21 and is connected to the camera 10 by its connector 17 via adata bus as well as address and control buses through which addresses,read/write enable signals, chip-select signals, stobes and clocks arepassed. The connector 17 may have power feeder lines for the memory 21.If one frame of a picture is expressed by data of 1M through 1.5M bits,the memory 21 can be a 24-frame memory device realized by two chips,where the SRAM has a storage capacity of 16M bits per chip.

The image pick-up section 30 has a camera lens 31, a diaphragm 32, ashutter 33, an image pick-up device 35, and other elements necessary fortaking still pictures, such as a photometer and range finder mechanisms,a view finder (not shown) and drive mechanisms for driving theseelements. Focusing the lens 31, operating the diaphragm 32 and actuatingthe shutter 33, etc., are controlled by system controller 11. As will bedescribed later, the system controller 11 operates the image pick-upsection 30, such as the shutter 33, after verifying the electricalconnection between the memory cartridge 20 and the camera 10.

A solid-state image pick-up device such as a CCD or MOS is employedadvantageously as the image pick-up device 35. The solid-state imagepick-up device 35 has an image pick-up cell array 34 to which a colorfilter is attached. In response to a clock signal received from asynchronizing signal generating circuit 43, the image pick-up devicesuccessively outputs a color-modulated video signal in the form of a dot(pixel) sequence. In the image pick-up device 35, any suitable array ofphotosensitive cells constituting the image pick-up cell array 34,namely any suitable number of pixels of the photosensitive region, canbe used. Also, the array of color segments of the color filter can be ofany type.

The video signal output of the image pick-up device 35 is applied to theanalog-digital converting and signal processing circuit 12. As mentionedabove, the circuit 12 converts the analog input video signal into thecorresponding digital data of e.g. eight bits and outputs the resultingdigital signal to the connector 17 via a changeover switch circuit 48(terminal a). The digital data is finally applied to the data bus of thememory cartridge 20.

The system controller 11 controls the overall operation of the apparatusin response to a command signal from a control and display panel 45.Control signals from the system controller 11 are applied tosynchronizing signal generating circuit 43, image pick-up section 30,analog-digital converting and signal processing circuit 12, a codegenerating circuit 42, and a code checking circuit 41. The systemcontroller 11 is also adapted to monitor the status of each of thecomponents of the apparatus.

The system controller 11 also functions to control primarily the writingof data in the memory 21 of memory cartridge 20 and has its bus, whichis for transmitting a write address, write-enable signal, chip-selectsignal, clock and the like, connected to the connector 17.

After loading of the memory cartridge 20 in camera 10 has been sensed bya connection sensing circuit 60, power is supplied from a power supplycircuit 50 to operate the system controller 11.

The system controller 11 is advantageously constructed as a processingsystem to which a memory 44 for storing e.g. various data and programsis connected by a bus. The memory 44 also holds information relating tothe type of image pick-up device 35 used by the apparatus, such asinformation relating to the number of pixels of the image pick-up cellarray 34, and information relating to the array of color segments in thecolor filter. For example, the information relating to the number ofpixels of the image pick-up cell array 34 may be in the form of datarepresenting the number of horizontal pixels and the value of the numberof horizontal scanning lines, or may be in the form of a code specifyingthe type of array. The information relating to the array of colorsegments of the color filter can advantageously be in the form of a codespecifying the type of array.

The code generating circuit 42 is a coding circuit which generates asignal representing a code corresponding to the command from the systemcontroller 11. The latter provides the code generating circuit 42 with acommand relating to the number of pixels of the image pick-up cell array34, and a command relating to the array of color filter segments. Theoutput of the code generating circuit 42 is connected to the changeoverswitch circuit 48 (terminal b). The changeover switch circuit 48 is aselector circuit which, under the control of the system controller 11,selects one of its connection positions (terminals a, b, c) so that thedata bus connected to the memory 21 will be connected to one of thecircuits 12, 41, 42.

The synchronizing signal generating circuit 43 is controlled by thesystem controller 11 and provides the image pick-up device 35 with drivesignals such as clock and address signals for driving the image pick-updevice 35 so that the latter will output a video signal.

The control and display panel 45 has a shutter release button andvarious manually operated buttons for automatic/manual settings,photometer setting, white balance adjustment and the like. The panel 45is manipulated by the operator to input commands to the apparatus, thesecommands being applied to the system controller 11. The panel 45 alsohas a display function in which signals indicative of the status of theapparatus are received from the system controller 11 and displayed forthe operator to see.

The power supply circuit 50 supplies electric power to the variousfunctional portions of the electronic still video camera 10 and isplaced in a state capable of performing this operation in response to asignal from the connection sensing circuit 60 indicating that aconnection between the memory cartridge 20 and the camera 10 has beensensed. The supply of power from the power supply circuit 50 to thesystem controller 11 and other functional portions is turned on and offby a power switch 49 manually operated by the operator. Accordingly,when the connection sensing circuit 60 issues a signal indicating thatthe aforementioned connection has been sensed and, moreover, the powerswitch 49 is turned on by the operator, power is supplied to the systemcontroller 11 and the other functional elements so that the controllerand functional portions begin operating. As long as the signalindicative of connection is not received from the connection sensingcircuit 60, the power supply circuit 50 will not deliver power to thesefunctional portions and, hence, the electronic still video camera 10will not perform a photographic operation, even if the power switch 49is turned on, as will be described in further detail below. In FIG. 5,the power supply lines for supplying power from the power supply circuit50 to the functional portions are deleted. The system controller 11 mayhave a supplemental battery which causes the controller to be standbymode.

The connection sensing circuit 60 is for sensing that the memorycartridge 20 has been connected to the camera 10 by the connectorportion 18 included in connector 17. When connection is sensed, thecircuit 60 outputs a signal to this effect to the power supply circuit50.

A specific example of the connection sensing circuit 60 is illustratedin FIG. 6.

As shown in FIG. 6, one line for supplying power to the systemcontroller 11 is connected to the negative electrode of a power supply58 and to ground. Another line is connected to the positive electrode ofthe power supply 58 via the power switch 49 and connector 18. When thememory cartridge 20 is loaded in the camera 10, a switch contactor 18Aof connector 18 is pressed in such a manner that two terminals 18a, 18b(which correspond to terminals 14a, 14b in FIG. 3) of the connector 18are connected to each other.

By virtue of this circuitry, the two terminals 18a, 18b of the connector18 are connected together as a result of the memory cartridge 20 beingloaded in the camera 10, so that the effect is the same as that producedby the limit switch 16. By the operator's turning on the power switch49, the power supply 58 delivers electric power to the system controller11 to initiate the operation of the same.

Since the two terminals 18a, 18b of connector 18 will not be connectedwhen the memory cartridge 20 has not been loaded in the camera 10, powerfrom the power supply 58 will not be delivered to the system controller11 even if the operator turns on the power switch 49. The systemcontroller 11 is in just its standby state.

Another example of the connection sensing circuit 60 is illustrated inFIG. 7.

In the example of this circuit also one line for supplying power to thesystem controller 11 is grounded and the other line for supplying poweris connected to one terminal of the power switch 49. The other terminalof the power switch 49 is connected to the drain of a field-effecttransistor (FET) 61. The source of FET 61 is connected to the positiveelectrode of the power supply 58 and to one terminal 18a of theconnector 18, the latter via a resistor 63. The gate of FET 61 isconnected to the one terminal 18a of connector 18 via an inverter 62.The negative terminal of the power supply 58 is connected to ground. Thememory cartridge 20 has two terminals 24a, 24b that are to be connectedto the terminals 18a, 18b, respectively. The terminals 24a, 24b areconnected together.

In the circuit of FIG. 7, the two shorted terminals 24a, 24b of memorycartridge 20 are connected to the two terminals 18a, 18b of connector 18when the memory cartridge 20 is loaded in the camera 10. Since thiscauses the two terminals 18a, 18b of connector 18 to be shortedtogether, the ground level is applied to the inverter 62, so that ahigh-level voltage is impressed upon the gate of FET 61. A currenttherefore flows across the source and drain of FET 61. Accordingly, inresponse to closure of the power switch 49 by the operator, power fromthe power supply 58 passes through the FET 61 and is supplied to thesystem controller 11.

The two terminals 18a, 18b of connector 18 are open when the memorycartridge 20 is not loaded in the camera 10. Therefore, a positivevoltage from the power supply 58 is inputted to the inverter 62 throughthe resistor 63, and a low-level voltage is impressed upon the gate ofthe FET 61. As a result, the source and drain of the FET 61 are cut offfrom each other. Therefore, power from the power supply 58 will not bedelivered to the system controller 11 even if the operator closes thepower switch 49.

Thus, in accordance with the circuit of this example, power from thepower supply 58 will be supplied to the system controller 11 by theoperator's turning on the power switch 49 provided that the memorycartridge 20 has been loaded in the camera 10.

The operation of the apparatus will now be described with reference toFIG. 5.

When the memory cartridge 20 is loaded in the camera 10 by theconnectors 17, 18, loading of the memory cartridge 20 is sensed by theconnection sensing circuit 60 via the connector portion 18. Since thepower supply circuit 50 is thus rendered connectable to the systemcontroller 11, power from the power supply circuit 50 is delivered tothe system controller 11 when the operator turns on the power switch 49.

The system controller 11 causes the changeover switch circuit 48 to beconnected to the code generating circuit 42 (terminal b) and providesthe code generating circuit 42 with a signal instructing this circuit togenerate a checking code. The code generating circuit 42 responds bygenerating a one-bit checking code signal. This signal is delivered tothe memory 21 via the changeover switch circuit 48, connector 17 anddata bus and is stored at a predetermined address of the memory 21.

Next, the system controller 11 connects the changeover switch circuit 48to the code checking circuit 41 (terminal c) and transmits a signal,which is indicative of the address at which the checking code has beenstored, as well as a control signal instructing a read operation, to thememory 21 through the connector 17 and the address and control buses,thereby causing the checking code to be read out of the memory 21. Thechecking code thus read is inputted to the code checking circuit 41through the connector 17 and switch 48. The code checking circuit 41checks to determine whether this code is identical with the codegenerated by the code generating circuit 42.

Upon confirming that the two codes are identical, the code checkingcircuit 41 sends the system controller 11 a signal indicative of the endof the checking operation. The system controller 11 responds to thissignal by again connecting the changeover switch circuit 48 to the codegenerating circuit 42, causing the code generating circuit 42 togenerate codes indicative of information relating to the number ofpixels of the image pick-up cell array 34, namely pixel numberinformation, information relating to the array of color filter segments,namely color separation information, and other information necessary atthe time of playback, and causing these codes to be stored in the memory21.

After the codes indicative of the information needed for playback arestored in the memory 21, the system controller 11 supplies the variouscomponents of camera 10 with power from the power supply circuit 50.This makes it possible for the operator to actuate the shutter 33 bypressing the shutter release button.

The operator takes a picture of a subject by manipulating the controland display panel 45. Pressing the shutter release button opens theshutter 33 so that one frame of the picture of the subject is picked upby the image pick-up device 35. In accordance with the clock provided bythe synchronizing signal generating circuit 43, the image pick-up deviceoutputs the picture in the form of a dot sequential video signal. Atthis time the system controller 11 connects the changeover switchcircuit 48 to the processing circuit 12 (terminal a) in advance.

The dot sequential video signal is converted into the correspondingdigital data by the analog-digital converting and signal processingcircuit 12 before being outputted to the connector 17 through thechangeover switch circuit 48.

Along with the digital video signal, the system controller 11 deliverssuch control signals as a write address, write-enable signal,chip-select signal and clock signal to the memory 21. In synchronizationwith this, the digital video signal inputted through the connector 17 issequentially written in successive storage locations of the memory 21.Thus, video signal data consisting of a picture of one frame are storedin a storage area of the memory 21.

The video signal stored in memory 21 in the apparatus of the presentembodiment is played back by a playback apparatus 70 having aconstruction of the type exemplified in FIG. 8. The playback apparatus70 has a connector 78 to which the memory cartridge 20 is connected inattachable/detachable fashion and which serves to connect a read-outdata bus of the cartridge 20 to a signal processing circuit 72. Addressand control buses of the memory cartridge 20 are connected to a controlcircuit 71 via the connector 78.

The signal processing circuit 72 subjects the input digital video signalto color separation and to the necessary video signal processing, suchas white-balance adjustment and tone (γ) correction. The result of thisprocessing is outputted to a digital-analog converter (DAC) 73. Dataneeded in order to perform this video signal processing suitably, suchas pixel number information regarding the image pick-up device 35 andcolor separation information, both of which are for the purpose ofperforming color separation, are set in the signal processing circuit 72from the control circuit 71, with the signal processing circuit 72executing the video signal processing on the basis of the setinformation.

The aforementioned digital-analog converter 73 converts the output videosignal of signal processing circuit 72 into the corresponding analogsignal and delivers the analog signal to an NTSC processing circuit 74.The latter includes a matrix and encoder for forming this analog signalinto a luminance signal and color difference signal and for convertingthese signals, along with a synchronizing signal from the controlcircuit 71, into an NTSC composite video signal outputted to a pictureoutput unit, such as a video monitor 75 and/or printer, by way ofexample. The monitor 75 outputs the composite video signal as a visiblepicture.

The elements of the playback apparatus 70 are controlled by the controlcircuit 71. The latter is advantageously constructed as a processingsystem to which a control and display panel 77 and a data file 76 areconnected. The control and display panel 77 has a playback button andvarious manually operated buttons such as a frame designating button,white balance adjusting button, tone adjusting button and the like. Thepanel 77 is manipulated by the operator to input commands to theapparatus, these commands being applied to the control circuit 71. Thepanel 77 also has a display function in which signals indicative of thestatus of the apparatus are received from the control circuit 71 anddisplayed for the operator to see.

The data file 76 is a memory device which holds various data necessaryfor the operation of the control circuit 71 and is constituted by a ROM,by way of example. The data held in the data file 76 contains pixelnumber information and color separation information of the image pick-updevice 35 with regard to the video signal stored in the memory 21 ofmemory cartridge 20.

In response to an instruction inputted by the operator at the controland display panel 77, the control circuit 71 supplies the control bus ofthe memory 21 with a control signal, which is for reading data out ofthe memory 21, in accordance with a predetermined basic frequency. Thus,video signal data of a designated frame, as well as the pixel numberinformation and color separation information of the image pick-up device35, are read out to the signal processing circuit 72 from the memory 21.

Codes indicating the pixel number information and color separationinformation are accepted by the control circuit 71 from the signalprocessing circuit 72. The control circuit 71 retrieves the data file 76in accordance with these codes, searches for the pixel number data andcolor separation data and outputs the same. In accordance with theretrieved and outputted data, the control circuit 71 decides the rate ofthe control signals, such as the clock signal, that are to be suppliedto the signal processing circuit 72 and digital-analog converter 73.Furthermore, data necessary for the video signal processing to beperformed appropriately, such as the pixel number information and colorseparation information of the image pick-up device 35 for performingcolor separation, are set in the signal processing circuit 72 inaccordance with the rate decided.

The control circuit 71 thus reads the video signal of the designatedframe out of the memory 21 and inputs this signal to the signalprocessing circuit 72. The latter separates the inputted dot sequentialvideo signal into color signals, e.g. red (R), green (G) and blue (B),in accordance with the pixel clock provided by the control circuit 71.This color separation is carried out in accordance with the pixel numberinformation and color separation information that has been set in thesignal processing circuit, namely in dependence upon the number ofpixels and the color filter segment array of the image pick-up cellarray 34 of image pick-up device 35 used in the camera 10. Accordingly,the playback apparatus 70 is capable of coping with the pixel array andcolor filter segment array of any system.

The signal processing circuit 72 also corrects a shift in white colorbalance caused by the color temperature of the light source when imagingis performed by the image pick-up device 35, and corrects a shift intone caused by a non-linear characteristic of the image pick-up device35. The video signal data outputted by the signal processing circuit 72is converted into an analog signal by the digital-analog converter 73, aluminance signal and color difference signal are obtained by the NTSCprocessing circuit 74, and the output of circuit 74 is delivered as anNTSC composite video signal. Finally, the signal is played back as avisible picture by the video monitor 75 and/or printer.

In this embodiment, the processing circuit 74 processes signals in anNTSC system. However, it goes without saying that an arrangement can beadopted in which the processing circuit 74 processes not only signals inan NTSC system but also in a PAL system or other standard televisionsignal system, such as SECAM.

Thus, in accordance with the present embodiment, the arrangement is suchthat power from the power supply circuit 50 is delivered to the systemcontroller 11 by the operator closing the power switch 49 after loadingof the memory cartridge 20 has been sensed by the connection sensingcircuit 60. Accordingly, if loading of the memory cartridge 20 is notsensed, power will not be supplied from the power supply circuit 50 evenif the operator closes the power switch 49. Accordingly, a picturecannot be taken as long as the memory cartridge 20 is incorrectlyloaded. This makes it possible to avoid the problem that occurs in theprior art, namely a situation in which, when the memory cartridge 20 isincorrectly loaded, the operator shoots pictures is spite of this fact,with the result that the resulting picture cannot be stored in thememory 21 of the memory cartridge 20.

Furthermore, in accordance with the embodiment, when the loading of thememory cartridge 20 has been verified, first the code generating circuit42 generates information necessary for playback, such as colorseparation information, this information is written in the memory 21,and triggering of the shutter 33 by the shutter release button isenabled after the writing operation ends. Since a photographic operationis thus made possible only after the information necessary for playbackis written in memory 21 beforehand, it is possible to prevent thisinformation from not being stored in the memory 21. In addition, sincethe color separation information, etc., is written in memory 21 inadvance, the burden of controlling writing operations can be eliminatedwith regard to the system controller 11. For example, the burden on thesystem controller 11 would be great if the color separation informationwere to be written in memory 21 in e.g. a blanking interval of the videosignal in concurrence with the writing of the video signal in memory 21.

In accordance with the present embodiment, power from the power supply50 is capable of being supplied to the system controller 11 afterloading of the memory cartridge 20 is sensed, and the shutter is capableof being triggered after information such as the color separationinformation is written in the memory 21. As a result, power is notsupplied prior to correct loading of the memory cartridge 20, and thepower necessary for photography is not supplied before photography ispossible. This makes it possible to prevent a drop in the capacity ofthe power supply due to wasteful consumption of power.

As many apparently widely different embodiments of the present inventioncan be made without departing from the spirit and scope thereof, it isto be understood that the invention is not limited to the specificembodiments thereof except as defined in the appended claims.

What is claimed is:
 1. A digital electronic still video camera to whicha memory cartridge is connected in a loadable/unloadable manner, thememory cartridge storing, in the form of digital data, a video signalrepresenting a still picture, the camera comprising:connecting means towhich the memory cartridge is electrically connected in aloadable/unloadable manner; image pick-up means, having a solid-stateimage pick-up device, for imaging light of a subject received by saidsolid-state image pick-up device and for outputting a video signalrepresenting the subject; signal converting means for converting thevideo signal outputted by said image pick-up means into a correspondingdigital signal and for outputting the digital signal to said connectingmeans; and control means for controlling said image pick-up means toperform imaging and said signal converting means to convert theoutputted video signal into the digital signal, and for supplying saidconnecting means with a control signal for controlling writing into thememory cartridge, said control means comprisinginformation generationmeans for generating information for verifying that the memory cartridgehas been electrically connected to the camera through said connectingmeans, and information verifying means for verifying the informationgenerated, said control means transmitting the information generated bysaid information generating means to the memory cartridge for storagetherein, reading the stored information from the memory cartridge, andenabling each functional part of the camera to perform a photographicoperation after said information verifying means verifies that thegenerated information is identical to the stored information read fromthe memory cartridge.
 2. A digital electronic still video camera towhich a memory cartridge is connected in a loadable/unloadable manner,the memory cartridge storing, in the form of digital data, a videosignal representing a still picture, the camera comprising:connectingmeans to which the memory cartridge is electrically connected in aloadable/unloadable manner; image pick-up means, having a solid-stateimage pick-up device, for imaging light of a subject received by saidsolid-state image pick-up device and for outputting a video signalrepresenting the subject; signal converting means for converting thevideo signal outputted by said image pick-up means into a correspondingdigital signal and for outputting the digital signal to said connectingmeans; and control means for controlling said image pick-up means toperform imaging and said signal converting means to convert theoutputted video signal into said corresponding digital signal, and forsupplying said connecting means with a control signal for controllingwriting into the memory cartridge, said control meanscomprisinginformation generation means for generating information forverifying that the memory cartridge has been electrically connected tothe camera through said connecting means, the information generatedbeing a checking code having a number of bits equivalent to a number ofdata input/output terminals of the camera, and information verifyingmeans for verifying the information generated, said control meanssending the information generated by said information generating meansto the memory cartridge and enabling each functional part of the camerato perform a photographic operation after said information verifyingmeans verifies that the generated information has been stored in thememory cartridge, after the memory cartridge is loaded in the camera. 3.The camera according to claim 1, wherein the information generated bysaid information generating means includes information directingplayback of the still picture stored in the memory cartridge.
 4. Thecamera according to claim 1, further comprising:loading sensing meansfor sensing that the memory cartridge has been loaded in the camera,said loading sensing means supplying electrical power from a powersupply means of the camera to said control means to thereby enableoperation of said control means upon sensing that the memory cartridgehas been loaded in the camera.
 5. A digital electronic still videocamera to which a memory cartridge is connected in a loadable/unloadablemanner, the memory cartridge storing, in he form of digital data, avideo signal representing a still picture, the cameracomprising:connecting means to which the memory cartridge iselectrically connected in a loadable/unloadable manner; image pick-upmeans, having a solid-state image pick-up device, for imaging light of asubject received by said solid-state image pick-up device and foroutputting a video signal representing the subject; signal convertingmeans for converting the video signal outputted by said image pick-upmeans into a corresponding digital signal and for outputting the digitalsignal to said connecting means; and control means for controlling saidimage pick-up means to perform imaging and said signal converting meansto convert the outputted video signal into the digital signal, and forsupplying said connecting means with a control signal for controllingwriting into the memory cartridge, said control meansgeneratinginformation, in information generating means, for verifying that thememory cartridge has been electrically connected to the camera throughsaid connecting means, transmitting the generated information to thememory cartridge for storage therein, reading the generated informationstored within the memory cartridge, verifying, in information verifyingmeans, if the generated information is identical to the stored generatedinformation read from the memory cartridge, and enabling each functionalpart of the camera to perform a photographic operation when saidinformation verifying means verifies that the generated information isidentical to the stored information read from the memory cartridge. 6.The camera according to claim 5, wherein the information generated bysaid information generating means is a checking code having a number ofbits equivalent to a number of data input/output terminals of thecamera.
 7. The camera according to claim 5, wherein the informationgenerated by said information generating means includes informationdirecting playback of the still picture stored in the memory cartridge.8. The camera according to claim 5, further comprising:loading sensingmeans for sensing that the memory cartridge has been loaded in thecamera, said loading sensing means supplying electrical power from apower supply means of the camera to said control means to thereby enableoperation of said control means upon sensing that the memory cartridgehas been loaded in the camera.
 9. A method of verifying electricalconnection of a loadable memory cartridge and a camera connectablethrough a plurality of terminal pairs comprising the stepsof:transmitting to the memory cartridge through the plurality ofterminal pairs, under direction of control means, generated informationfor storage within a specific memory address of the memory cartridge;reading the stored generated information from the specific memoryaddress; comparing the generated information and the stored generatedinformation, in a comparison means, to determine coincidence thereof;and generating a signal indicative of coincidence and verification ofelectrical connection of the camera and the memory cartridge through theplurality of terminal pairs.
 10. The method of verifying electricalconnection of a loadable memory cartridge and a camera of claim 9comprising the further steps of:transmitting to the memory cartridgenewly generated information, different than the generated information,for storage in the specific memory address of the memory cartridge upondetermination of non-coincidence of the generated information and thestored generated information; and repeating said comparing andgenerating steps using the newly generated information to determinecoincidence.
 11. The method of verifying electrical connection of aloadable memory cartridge and a camera of claim 9, comprising thefurther steps of:transmitting to the memory cartridge the generatedinformation for storage in a second specific memory address, differentthan the specific memory address, of the memory cartridge upondetermination of non-coincidence of the generated information and thestored information of the specific memory address; and repeating saidcomparing and generating steps using the generated information of thesecond specific address to determine coincidence.
 12. A cameraelectrically connectable to a loadable memory cartridge through aplurality of terminal pairs, the memory cartridge storing, in the formof digital data a signal representing a picture, the cameracomprising:detection means for detecting loading of the memory cartridgeinto the camera and for providing power to the camera upon detection;transmitting means, operable under direction of control means, fortransmitting to the memory cartridge through the plurality of terminalpairs information from said control means for storage therein in aspecific memory address upon receipt of power to the camera; readingmeans for reading out the information stored in said specific memoryaddress; and electrical connection verification means, coupled to saidcontrol means and said reading means, for comparing and determiningcoincidence between the information and stored information to generate asignal as a result of coincidence indicative of electrical connectionbetween the camera and memory cartridge through said plurality ofterminal pairs.
 13. The camera of claim 12, said detection meanscomprising:power source means for providing power for the camera; apower supply switch, coupled to said power source means and controlmeans, for providing power from said power source means to said controlmeans, and the camera, upon activation thereof; and an inversion gate,coupled to a first terminal of a first pair of said plurality ofterminal pairs within the camera, for providing a power supply signal toturn on said power supply switch directing supply of power to saidcontrol means and camera, a first terminal of a second pair of saidplurality of terminal pairs coupled to a ground potential of said powersource means within the camera, and second terminals of said first andsecond pairs of said plurality of terminal pairs coupled together withinthe memory cartridge, the ground potential of said first terminal ofsaid second pair incident upon said first terminal o said first pair,and said inversion gate, upon loading of the memory cartridge within thecamera to provide the power supply signal to said power supply switch.14. The camera of claim 12, said camera a digital electronic still videocamera and said digital data representing a still picture.